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姓名 劉力維(Li-Wei Liu) 查詢紙本館藏 畢業系所 土木工程學系 論文名稱 水流墩前湧波之探討
(Bow wave and Hydraulic jump induced by cylindrical piers in open channel flows)相關論文 檔案 [Endnote RIS 格式]
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摘要(中) 本文以實驗及數值計算分析超臨界流況下,橋墩受水流沖擊所造成的墩前湧波,探討橋墩尺度對振幅、頻率的影響;實驗於亞臨界流況下,利用超音波速度剖面儀(UVP)量測墩前速度場分佈,進一步探討墩前射流之分離位置及流場中頻率的特性,並透過數值模Truchas分析墩前射流位置及渦流分佈。實驗結果顯示,沖擊高度與上游福祿數呈正比之關係;UVP 能有效量測邊界層厚度及墩前渦流尺寸;透過數值模式,能進一步分析細部流場變化,如:渦度分佈、底床剪應力。本研究之結果可幫助於瞭解亞、超臨界流況中墩前沖擊高度與上游福祿數的關係,可供相關工程設計之參考。 摘要(英) Bow waves in front of cylindrical piers under different flow conditions, especially supercritical flows, are explored in this study by employing both flume experiments and 3D numerical simulation. An ultrasonic velocity profiler (UVP) is used to measure the downward/upward flow right in front of the pier, and the downward flow and the stagnation point along the profile are also measured. The magnitudes and the frequencies of bow waves are analyzed by image analysis. The vortex sizes are mainly determined by pier diameter alone. The dimensionless amplitude of bow waves is proportional to the square of upstream Froude numbers. The numerical simulations for piers in shallow water show that the shear stresses on the floor exhibit maximum value at the downstream sides, which is due to pier-induced surface drawdown and wake separation. 關鍵字(中) ★ 超臨界流
★ 墩前湧波
★ 沖擊高度
★ 底床剪應力
★ 頻譜分析關鍵字(英) ★ Spectrum analysis.
★ Bed shear stress
★ Surge height
★ Bow wave
★ Supercritical Flow論文目次 摘要 ................................................... I
ABSTRACT.............................................. ..II
目錄 .................................................. III
表目錄 .................................... ........... VII
圖目錄 ............................................... VIII
符號表 .................................................. X
第一章 緒論...............................................1
1-1 前言 ............................................ ....1
1-2 研究目的..............................................2
1-3 本文架構 .............................................3
第二章 文獻回顧 ......................................... 4
2-1 流場之特性頻率 .......................................4
2-2 圓柱渦流流場 ........................................ 5
2-3 墩前沖擊高 .......................................... 8
第三章 數值模式 ........................................ 11
3-1 模式簡介 ........................................... 11
3-2 控制方程式 ......................................... 12
3-3 大渦紊流模式 ........................................12
3-4 數值方法 ........................................... 15
3-4-1 有限體積法 ....................................... 15
3-4-2 流體體積法 ..................................... ..17
3-4-3 自由液面求解.......................................19
3-4-4 顯示投影法........................................ 21
3-4-5 程式運算流程 ......................................21
3-5 邊界條件及初始條件 ..................................22
3-5-1 不可滑動邊界...................................... 22
3-5-2 上游入流邊界 ......................................22
3-5-3 下游出流邊界 ..................................... 23
3-5-5 啟始條件 ......................................... 23
3-6 網格設計 ........................................... 23
3-7 數值穩定度 ......................................... 23
3-8 部分網格法 ......................................... 24
第四章 渠道定床實驗 .....................................26
4-1 實驗目的 ........................................... 26
4-2 實驗設備 ........................................... 26
4-3 實驗條件 ........................................... 30
4-4 實驗方法與步驟 ..................................... 31
4-4-1 脈衝波原則 ....................................... 31
4-4-2 量測角度 ......................................... 33
4-4-3 UVP 流速量測 ..................................... 34
4-4-4 實驗步驟 ......................................... 35
4-4-5 影像分析 ......................................... 36
4-4-6 頻譜分析 ......................................... 37
4-5 實驗結果 ........................................... 38
4-5-1 洩水閘門、堰流流量及UVP 流速計流量.................38
4-6 儀器限制及消除雜訊 ................................. 40
4-6-1 都普勒流速儀之優點及限制 ......................... 40
4-6-2 量測限制 ......................................... 40
4-6-3 消除雜訊的方式 ................................... 42
第五章 實驗結果與討論 .................................. 44
5-1 邊界層厚度 ......................................... 44
5-2 穩定流況 ........................................... 45
5-3 墩前沖擊高 ......................................... 45
5-4 沖擊高之頻譜分析 ................................... 47
5-5 墩前的分離點 ....................................... 48
5-6 墩前馬蹄型渦流尺度 ................................. 50
5-7 垂向速度之頻譜分析 ................................. 52
5-8 水躍段與下游之水平及垂向速度 ....................... 52
5-9 墩前水面線量測 ..................................... 54
5-10 數值結果 .......................................... 55
第六章 結論與建議 ...................................... 58
6-1 結論 ............................................... 58
6-2 建議 ............................................... 59
參考文獻 ............................................... 60
附錄 ................................................... 63參考文獻 1.吳益裕 (2007),「實用明渠水力學」,必中出版社,台中。
2.胡富雁(2007) ,「波狀水躍流場之水理分析」,碩士論文,國立中央大學土木工程學系,中壢。
3.陳浩、高冬光(1991),「橋梁水力學」,人民交通出版社。
4.經濟部水利署(2002),量水設備技術規範草案。
5.謝奕生(2000),「流體體積法之應用於水躍分析」,碩士論文,私立淡江大學水資源及環境工程研究所,淡水。
6.Ahmed, F and Rajaratnam, N. (1998) “Flow around bridge piers” J. Hydraulic Engineering., vol.124, No.3, pp.288-300.
7.Baker, C.J. (1978) “Vortex Flow Around the Base of Obstacles”, Ph.D. thesis, Univ of Cambridge, 123, pp. plus figure.
8.Baker, C.J. (1979) “The Laminar Horseshoe Vortex”, J. Fluid Mech., Vol.95, pp.347-367.
9.Ballio, F., Bettoni, C. and Frsnzetti, S. (1998) “ A Survey of Time-Averaged Characteristics of Laminar and Turbulent Horseshoe Vortices ,” J. Fluids Engineering, Vol.120, pp.233-242.
10.Blevins., (1990) “Flow-Induce Vibration”, VAN NOSTRAND REINHOLD.
11.Chorin, A. J.,(1968)“Numerical solution of the Navier-Stokes equations” Math. Comp., vol. 22, pp.745-762.
12.Dargahi, B. (1989) “The Turbulent Flow Field around a Circular Cylinder” Experiment in Fluid 8., Vol.8, pp.1-12.
13.Deardorff, J. W.,(1970)“A Numerical Study of Three-Dimensional Turbulent Channel Flow at Large Reynolds Number” J. Fluid Mech., vol. 41, NO. 2, pp.453-480.
14.Graf, W.H. and Yulistiyanto, B. (1998) “ Experiments on flow around a cylinder;the velocity and vorticity fields ,” J. Hydraulic Research, Vol.36, No.4, pp.637-653.
15.Henderson, F. M., (1966) ”Open channel flow” Macmillan Publishing co., pp.522.
16.Harlow, F. H. and Welch, J. E. (1965) “Numerical Calculation of the Time-Dependent Viscous Incompressible Flow of Fluid with Free Surface”, Physics of Fluid, vol. 8, pp.2182–2189.
17.Johnson, K. R. and Ting, C. K. (2003) ”Measurements of water surface profile and velocity field at a circular pier” J. Engineering mechanics., vol.129, No.5, pp.502-513.
18.Kubo, K.(1988)”Experiment Study on Horseshoe Vortex in the Upstream Front of Cylindrical Structure”, Modelling Soil-water-structure Interactions, Kolman et al., pp.117-126.
19.Lienhard, J. H. (1966) “Synopsis of Lift, Drag and Vortex Frequency Data for Rigid Circular Cylinders,” Washington State University, College of Engineering, Research Division Bulletin, pp.300.
20.Lin, C., Lai, W.J. and Chang, K. A. (2003) “Simultaneous Particle Image Velocimetry and Laser Doppler Velocimetry Measurements of Periodical Oscillatory Horseshoe Vortex System near Square Cylinder-Base Plate Juncture” Dept. of Civil Engineering, National Chung-Hsing Univ., J. Hydraulic Engineering, pp.1173-1188.
21.Liu, M., Rajaratnam, N. and Zhu, David Z. (2004) ”Turbulence Structure of Hydraulic Jumps of Low FroudeNumbers”, J. Hydraulic Engineering, Vol.130, No.6, pp.511-520.
22.Muzzammil, M. and Gangadhariah, T. (2003) “The mean characteristics of horseshoe vortex at a cylinder pier ” J. Hydraulic Reach., Vol.3, pp.285-297.
23.Met-Flow SA, (2002) “UVP-DUO Monitor User’s Guide”, Switzerland,http://www.met-flow.com.
24.Rider, W. J. and Kothe, D. B.(1998)“Reconstructing Volume Tracking”Journal of Computational Physics, vol. 141, pp.112-152.
25.Schlichting, H. (1979) Boundary-Layer Theory, McGraw-Hill Company, Vol.160, pp.32.
26.Wu, S., Rajaratnam, N. and Katopodis, C. (1998) “Oscillating Vertical Plane Turbulent Jet in Shallow Water”, Journal of Hydraulic Research, Vol.36, No.2, pp.229-234.
27.Wu, T. R. (2004)” A Numerical study of three-dimensional breaking waves and turbulence effects” Ph.D. Dissertation, Dept. of Civil Engineering, Cornell University, pp.1-84.指導教授 周憲德、吳祚任
(H.T.Chou、Tso-Ren Wu)審核日期 2008-7-24 推文 plurk
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